Kepo piezo elements for audio transducers kepo ft 347g 29b1 474 the keno piezo element 300 o 31 05khz is a 347mm diameter piezo element with a 30000nf30nf capacitance that can be used for a small audio transducer such as a buzzer kepo ft 347g 29b1 474 piezo element 300 ohm 31 05 khz 347mm